Can you Repair Underfloor Heating?

Repair Underfloor Heating – Is it possible?

When a customer is deciding to install underfloor heating, one of the most common questions asked is if you can repair underfloor heating ? Fortunately, the answer is yes.

Installing underfloor heating can be a quite costly investment. It gets covered in leveller and tiles are fixed over the top. How on earth can you repair underfloor heating if it goes wrong or stops working?

The good news is that to repair underfloor heating can be a fairly simple exercise. Listed below are possible reasons why it isn’t working and how you can repair underfloor heating problems:

1. Temperature sensor

If the thermostat is displaying a strange reading to normal, the floor sensor maybe faulty. Creative Tiles & Laminates always installs a second floor sensor as a backup to the first sensor. Then if the floor sensor does go, it isn’t a major job to swap which sensor is used by the thermostat.

If you do not have a secondary sensor, you will have to install a new floor sensor. Either dig into the grout lines (if wide enough) or dig up a tile so you can position it adjacent to the underfloor heating mat.

2. Thermostat

Try resetting the clock to the factory settings to check whether your thermostat is faulty. If the problem persists, you may need to change the thermostat.

3. Underfloor Heating Mat Cable

Underfloor Heating Cable Repair Kit

A. An accidental break in the cable.

We find that most repairs are necessary due to accidentally cutting into the electric cable.

Fortunately, this type of failure means you know exactly where the break is so you should be able to fix it using a cable repair kit.

Most electric underfloor heating mats are manufactured in the same way. This means that the break in the cables can be easily resolved by using a repair kit.

Each kit will repair one breakin the electric underfloor heating cable mat.

B. Location of failure unknown.

This is the trickiest and most expensive failure to fix but it is not impossible. You simply need to book an experienced underfloor heating electrician.

He will use various pieces of equipment including a thermal imaging camera to identify the site of the failure. Once the break is identified, he can simply dig up the tile above the break and fix the break. You can then arrange for a tiler to fit a replacement tile or you can do it yourself. Don’t forget to use flexible adhesive and grout.

Remember, most underfloor heating mats come with a lifetime guarantee. If the electrician determines that it is a manufacturers fault, the cost of the repair to the mat should be covered by the manufacturer.

We recommend checking out the terms of your manufacturers guarantee. You may have to contact the manufacturer, supplier or installer of your underfloor heating mat to authorise a visit by the specialist UFH electrician.

If you need to repair underfloor heating, or you require any further help or assistance,please contact Creative Tiles & Laminates or call 01922 610015.

About Susan

Joined Creative Tiles and Laminates as Marketing Manager in 2005. Complementing the senior management team containing 30+ years experience of fitting, flooring and customer services.

130 Responses to Can you Repair Underfloor Heating?

My electrical underfloor heating mats have been installed for a few months now but I find that if does continues to heat up even when the thermostat does not display the logo for “heating”. Therefore, I have to manually turn off the system on the on/off switch rather than controlling using the digital display.

Any suggestions on the cause of the issue? I have tried many of the options on the control box but to no avail.

Hi Chris
Thank you for your kind comments about our website.
Regarding your problem, you could be facing one of 3 issues:
1. You could have a faulty sensor – does it give a high reading, a low reading or just a strange reading?
2. There could be a wiring problem – such as if 2 sensors are wired in, then the underfloor heating will not work properly.
3. You have a faulty thermostat and the relay has failed – this could happen even with a relatively new stat (but at least it will still be under warranty).

Hi. I have under floor heating installed, one mat operating with one thermostat. It has been working perfectly fine for the past 10 years but recently when u switch it on the thermostat light goes on to green however the floor is not getting warm at all. We have swap the thermostats of the bedroom & the lounge but getting the same response. I would like to know what may be the problem & is the thermostat still in working condition if the light is still going on?

Hello Lanchia
Sometimes the thermostat can appear to be working when it isn’t. Usually the relay will fail in the stat, but there might not be any outward signs that it is no longer working, apart from the fact that the floor no longer gets warm. If you have had it 10 years then it is possible that it needs replacing. Remember, it is usually the sensors and stats that fail, rather than the mats which is why both of these of shorter manufacturer warranties. Our replacement thermostat is available by clicking here.
I hope this helps.
Regards
Susan

We have had ufh installed in the bathroom but the painter snagged the wire and tore it. This was repaired before the tiles were laid. However now the floor is down and we have turned it on there is a narrow strip in the middle of the floor that isn’t getting warm. Do you know why this could be?

Hi Adam
If you only had one mat fitted then it is not possible for part of it to work and part of it not to work. If part of it isn’t getting warm then it means there are no heating cables under that area of the floor for whatever reason.
Regards
Susan

I recently had my mat electric underfloor heating installed by bathroom fitting company but when they showed me the pictures taken before tiling two of the cables which were running through the floor were nearly touching (3mm away?) when it says in instructions manual they should be kept at minimum distance of 50mm and I’m now worried that once it’s plugged to test (waiting for 10 days after tiles are settled) the cables would melt as being too close and the whole system will fail to operate, what should I do should I try to use it or rectify the problem with qualified electrician experienced in the mats, is my warranty affected now? Was supposed to be lifetime warranty but they didn’t even fill in the booklet with the readings….

Hi Luiza
You are right, it is not good to have the cables running that close to each other as they can burn out if too close. It might work okay in the beginning but given time may fail.

I’m afraid that if your underfloor heating has been installed incorrectly, then this would void any warranty that you are supposed to have. The manufacturer simply would not cover any faults materialising as a result of poor installation.

I would say that it is better for you to get the problem rectified now. The bathroom company should be responsible for any errors in installation, at the end of the day you are paying them to give you a professional service. Hopefully, the bathroom isn’t too large and can be easily remedied.

Hi there. Thanks for a great blog post, but I need a little hand holding. My Wickes electric UFH system is in a ground floor extension which is actually the family bathroom ( Victorian terrace setup). The UFH was installed about 15 years ago under a stone tile floor. It worked for about 15 months then nothing – the thermostat appeared to be working but no heat in the floor. Today, the electrician said it was a faulty thermostat with no detectable break in the floor. But when he fit a new one, it blew! Very loudly! He tried another, and that just cut out. He thinks there may be more than one break in the floor. So what next? Do I risk fixing it for £400-500 or install a new UFH on top of the current floor? The room really needs UFH. Thanks!

Hello
As your underfloor heating is blowing, it is more than likely that there is a fault with the mat (or several). As long as you have spare tiles, then I would say call in the specialist ufh electrician. That is, unless you wanted to take the opportunity to update the bathroom design/style as it’s likely to cost considerably more for new underfloor heating and flooring.
Regards
Susan

Hi, I had an underfloor heating system installed and the resistance was measured before installation and after, and after a week now the resistance has dropped from 59 to 22 and had the thermostat installed shows all the right signs but the Mat seems to not be getting any power to heat up at all so have I just wasted £500. What could be the problem?

Hi Rez
The resistance figure changes as it heats up. If the floor doesn’t seem to be getting warm then check the sensor. Usually if the floor isn’t warming it is a problem with the power supply, controller (thermostat) or floor sensor. Whereas if the fault is causing tripping there is a fault with the mat.
Regards
Susan

Hi Susan, thanks for all the tips. I’m still head scratching. Installed 2 matts to one thermostat. When first turned on one side didn’t work so I got an electrician out to have a look and he could work it out. So turned it off and on again and now the side that wasn’t work is now working and side that was working has stopped. The thermostat hasn’t been installed under the tiles as there is still two more tiles to lay down. Any help would be much appreciated.

hello, what a wonderful set of information. We have had electric ufh installed in 3 rooms, 3 separate circuits. Laminate flooring on top. 2 rooms work fine, the other (huge) room does nothing at all! Thermostat works in terms of saying the correct temp and when I turn it up it shows the temp I want it to go to. Electrician is certain the circuit loop is intact and power goes all the way round. He has fiddled repeatedly with thermostat and replaced it. There is no heat coming through though. Builder and electrician have now said they can do nothing more and abandoned us. Any suggestions? We are in the UK.

We have electric under floor heating mats with a simple s control mechanical thermostat in all rooms. The house is a 3.5 year old bungalow, so the under floor heating isn’t very old. When we turn the thermostat on in the lounge it goes to green to say the floor is up to temperature, which it certainly isn’t. This is the case no matter what temperature we set the thermostat to. I replaced the thermostat with the one from the hall and the same issue. Is this likely to be the sensor under the floor? there was a fault with that when we first moved in and it was repaired though we didn’t experience the same issue with the thermostat.

Hi. My heat mat has developed a problem causing the the main RCD to trip out when it kicks on. My floor consists of 2 mats, one of which works fine. The other does not and shows no resistance whatsoever. Programmer works as it should and sensor shows resistance and seems to work fine.

By no resistance does this mean the cable has a clean break or could it be just the cable has been knicked on the side?

Hi Mark
From what you have described, if there is no resistance then you have a fault. It could be a short with the earth. I’m afraid the only way to fix this is by finding the fault by calling in a specialist ufh electrician. Go back to the installer or manufacturer if the mat is still under warrranty first, just incase they have their own specialists and to see what you are covered for under the guarantee.
Regards
Susan

We tested everything before and after installation of our electric underfloor heater. All seemed well except that I needed to set the thermostat to 30 degrees to make the floor even warm. A few months later the underfloor heating tripped the switch on the rcb. The electrician says this is caused by a short on the ufh.
Although the company supplying the mat is willing to pay to have this fixed it is on the condition that if there is a fault on the installation we will have to pay the £400 charge. We live in Penzance and the repairer lives in Reading.
If they say it’s the installation we could end up with this bill.
What are the chances of the installation being at fault given the above?

Hi Fletcher
In our experience, the repairers are usually very fair and the chances of faulty installations are low but they can’t be guaranteed. If you don’t try to get it repaired then you will just be without the underfloor heating which seems such a shame.
Regards
Susan

Our electric underfloor heating was turned on by our contractor last week. For the first few days all was well, but yesterday we noticed a buzzing/humming sound coming from the floor near the toilet / tub area. We have turned off the system. The contractor says he has never experienced anything like this and is coming back tomorrow to replace the controller, even though that’s not where the noise is originating from. We are nervous about a potential fire or electrical shock hazard, since at this point we can’t rule those out. Any advice?

Hi there,
I have faulty termostat that I want it to replace with new version. I got it from Reliance whitch is for electric, water or air. I got electrician to connect it for me and set it. But termostat show error message that can’t read probe. I got it another one similar and the same problem. Probe is good as I did get third one and works with it but I’m not happy with design and like to change. Is the probe that wouldn’t work with every Termostat?
What should I look for when look for another termostat that actually works with this probe. I cant change probe eider.
Kind regards Janusz

Hi Janusz
Although generally interchangeable, there might be compatability issues between some probes and thermostats as you have now discovered. The electric thermostats we install are only electric ones, no water or air as this seems superfluous as you are only trying to control the floor temperature. Without knowing which probe you have I really can’t advise which thermostats will work okay apart from sticking to the same supplier/manufacturer for both these items.
Regards
Susan

Hello, I’m after some advice please. Our underfloor heating was installed in Feb and all was working fine for 2 months… the temperature of the floor was the same all over. However recently we have noticed that the floor temperature is uneven. It gets very warm over by the sinks but the rest of the floor stays lukewarm maybe just even room temperature…but certainly not up to the temperature it should be! Unfortunately when it was installed the electrician didn’t take any resistance readings so I presume any warranty will be void? Any advice how to rectify would be appreciated.

Hi Dave
Do you know whether you have more than one mat fitted? If so, are they both operated through one sensor and thermostat? If that is the case, it sounds as if your stat and sensor are working fine but one of the mats has failed.
Did you supply the mat or was it supplied by someone else who also installed it? If the installer supplied it, go back to them and ask them to investigate. It will be their responsibility to get it back working again especially as it was only fitted a few months ago. If you have no joy with them or you purchased the underfloor heating yourself, you will need to contact the manufacturer directly. They should be able to provide support and assistance regarding finding the fault and correcting the problem.
Kind regards
Susan

My underfloor electric heating system is in my bath and walk-in shower. There was a break in the wire during installation near the shower drain. It was repaired with a manufacturer supplied kit consisting of butt connectors and heat shrink. The repair has now failed, I suspect due to water penetration of the splice. I see conflicting information regarding repair of the heating cable in a wet location. Some say it cannot or should not be done. What is your experience?

Hi Tim
The underfloor heating we use with laminate flooring is a carbon film system which has connectors at the end of each turn of the mat. Because of these connectors it should not be installed inside a bathroom. We only install a cable mat which is a sealed continuous system with any connectors situated outside of the bathroom.

On this basis, you probably shouldn’t have any connectors inside the bathroom. Given that yours is actually a wet room and especially that the repair is in a wet location, it should not be repaired as the connectors should be kept outside of a bathroom.

Firstly, we need to determine if you have more than one mat fitted. If so, are they both operated through one sensor and thermostat? If you do have multiple mats running off one thermostat and sensor and part of the flooring is not warming up then I’m afraid it is most likely that one of the mats has now broken (especially if it’s been working well for 11 years).
Hopefully, your mat has a lifetime guarantee in which case it should be covered by the manufacturer. So you would need to either contact the original installer (who will go back through the manufacturer) or you can contact the manufacturer directly.

If not covered, then you will need to instruct a underfloor heating specialist electrician (approximately £400-£500). They will be able to locate the fault in the mat, dig up the ceramic tile and fix the fault. And then you’ll just need to get the tile replaced (from those spares you kept just in case something happened).

We have just had electric ufh installed under engineered wood flooring by our builder. We have two zones with separate thermostats. The area installed in our dining room works but I have never felt any heat in the kitchen side. The builder tried to fob me off by saying they could feel it working and it just needs more time to heat up (already been on for a week). This morning the thermo control has a warning symbol and says that the floor sensor has short circuited.

How easy a fix will this be for the builders electrician? Will all the new floor have to come up? Can the electrician do it or do we need a specialist? Just looking to ensure that I am best armed with as much info as possible as the builder of course won’t be overjoyed if they have to spend more labour hours here to fix it and especially not if they have to buy us a new floor. I don’t know what the heating mays were only that the thermostats say Devi on them if that helps.

Hi Lisa
Yes, the floor sensor could have short circuited. It could simply be a faulty sensor or it could be down to the installation. It is very rare though that the whole floor would need to come up to be rectified.

I would recommend contacting the Devi helpline directly, especially as you have the warning symbol on the controller. They can then advise of the best steps to take next.
Kind regards
Susan

We have nuheat floors in 3 bathrooms& a kitchen. The have been working for the past 6 years. Recently all the thermostats are flashing. After several electricians who couldnot diagnose the problem, the last electrician said that there is a white wire that he needs to replace. These are not connected to the main panel somehow. He was supposed to come to fix it but disappeared. The electrician who did the work to begin with is out of business. I know the thermostats are ok. How do I fix this issue? please help.

Hi Pamela
It looks as if the Nu-heat underfloor heating is a wet based system and I’m afraid we can only help with electrical based ones. I’d recommend contacting the company directly as your product will most likely still be under warranty.
Kind regards
Susan

Hello, I really hope you can help me. 7-8 years ago we installed a film electric underfloor heating system with an Aube thermostat which up until now has worked fine. Two nights ago the heating stopped working (just as we have frosty nights!). The thermostat looks to all intents and purposes as if it is working, the only difference being that if you set a higher heat, it takes a lot longer to ‘respond’ and theoretically start heating – but no heat. It is currently showing a temperature that looks likely (12 degrees C, yesterday it was 15), so that gives an impression that the sensor is working. Please tell me it might just be a thermostat problem and that we just need to change that. Thanks in advance.

Hi Cathy
It does sound as if the floor sensor is still working and the temperature reading it is giving is that of the natural floor temperature. From your description, it is more likely that the relay has failed on the thermostat so you will need to replace the thermostat.
Kind regards
Susan

Hi, This might not be a usual question but I would just like some advice. My partner and I have recently rented a house where the sole heating is the underfloor heating. However, within a week of moving in one of the underfloor heating mats has had an element(?) broken and subsequently overheated luckily whilst I was in as it caused burns to the furniture and rug that was on it. We now have the estate agent saying that there are no engineers that deal with underfloor heating in the country so it cannot be fixed to give us heating. They also incinuated that it’s our fault as the rug and furniture could have caused this to happen as it was too much for the system to handle. I was just wanting to know if any of what they are saying is true as we haven’t had any problems with other underfloor heating systems before this.
Any advice would be great.

Hi Alexandra
The estate agent is incorrect in his first statement in that there are no engineers to deal with underfloor heating problems in this country, of course there are, but of course it may be quite costly to fix.

However, his second statement is correct, as all underfloor heating manufacturers will advise you not to cover the heated floor as this can cause overheating. Most furniture will sit on legs and not directly onto the floor allowing some air gaps, but rugs in particular should be avoided as they have direct contact with the flooring.

Can you change the control module and leave the underfloor mats and cabling? The system I have in an old bathroom works but the control module is very non-intuitive, being very difficult to set. This has become even more evident having put in ‘Warmup’ underfloor heating in another bathroom – which is very easy to use.

I don’t want to have to rip up the tile flooring if I can just change the module.

Hi Doug
Don’t worry you shouldn’t need to rip up the tile flooring as most electric underfloor heating thermostats are fully interchangeable. Simply choose one that you are happy using and swap it out.
Kind regards
Susan

I have read through all the previous posts to try to understand what the problem is with my electric underfloor heating in the bathroom. My problem is slightly different in that the thermostat is showing 31 degrees even though I have set it at 35 degrees. The whole floor is getting heat but not an even temperature through out. Some of the floor nearer to the thermastat is a lot warmer than the rest of the floor. It was only one continuos mat that was fitted. Is this a thermastat problem or is it may? Many thanks for any advice you can provide.

Hi Sally
Most underfloor heating systems do not go really go above 28 degrees for fire safety reasons. So having yours set to 35 degrees is really too high and I would suggest having a setting of about 26 degrees. To be honest, you probably wouldn’t really be able to tell the difference between it being at 26 degrees and 31 degrees as the tile isn’t meant to be hot, just slightly warm and not cold.

Also underfloor heating systems are not designed to provide and even heating across the floor as they are designed to warm the room. Hence you should expect to have warmer and cooler parts over the floor. From what you have said it appears as if your underfloor heating is working within normal parameters.

I have an American ¨TEC¨ brand heating mat with a honeywell thermostat and I do believe I have a failed sensor. It worked for only a few days, then quit. Your system of installing a second sensor as backup is brilliant, but sadly I didn´t know about it until it was too late.

I do believe I will have to install a new sensor. My question- obviously there are many locations to install the new sensor, and I would like to install it in the least visible spot, but where?

The directions for mine call for installing under the mat, but can i install this replacement sensor right NEXT to the mat?

My plan is to wire in the new sensor as soon as I get it, then tape it to the top of the heated area, until I find a spot as close to the edge as possible but that still works properly. Then I would chip out grout and lift tile and install it properly. And yes, I would install a spare ; )
Your thoughts?

Hi Joe
Putting the sensor in a grout line is perfectly acceptable and we would suggest this is the way to go. However, one tile in of the heated area would be better than close to the edge. Also when raking out the grout, make sure you don’t go any deeper than the tile thickness to avoid the risk of damaging the heating cable.
Kind regards
Susan

Hi. I got issue with my electric underfloor heating. When i installed it 2 month ago, it worked fine. And floor also heated fine (was even hot if leave on high temp) now after 2 month i noticed, that all floor heats but on low temperature, no matter which temp i set, floor is little bit warm and no matter how high temp i set. ( warm all space as from beginning). Thermostat shows adequate temperature but floor doesnt heat to hot anymore. Any suggestion what can cause this problem ?

Hi Eddie
Yes it is possible to check, but you need to know what resistance you’re looking for and what settings to have the multimeter on. For this reason you need to call in a qualified electrician.
All the best
Susan

I have a mat which has worked fine for several years. Recently it started to trip the circuit breaker when it came on. I have checked the sensor and it gives a sensible resistance. Also the mat itself has a resistance of around 40 ohms, which would equate to 1200W, about 5.5 Amps, so all seems OK. Is this a faulty thermostat; the thermostat is switching but maybe it causing a surge somehow, or some other issue?

Hi Alan
It could be the thermostat, however, the earth shielding can degrade causing a short even though the heating cable and its resistance is fine (this actually happened to my underfloor heating mat at home). An electrician could check for this as it is an ‘earth leakage’. The cheapest fix would be to try a new thermostat, but if this doesn’t work, then I’m afraid you will need to get an underfloor heating specialist in to locate the fault.
All the best
Susan

Hi Susan
I’ve dropped a clanger!
I didn’t order the wrong size mat but my room size has now changed leaving me with 2sqm too large a mat.
I am warned this can’t be cut under any circumstances and yet the terminator looks as though it is only sophisticated heat-shrink. I also see that repair ‘joiners’ can be utilised. As I have no guarantee anyway (installed outside U.K.) and do not have the option to reorder in time for the floor to be laid – what can you tell me about the terminal before I cut into it?

Hi Peter
It is unfortunate that your room size has now changed but under no circumstances should you shorten a mat. The correct size of mat should be installed for the correct size of room. I’m afraid that if you want to get into the manufacturing details of the mat, then it is best if you contact the manufacturer directly.
I’m sorry that I couldn’t help you further.
Kind regards
Susan

Hi, we have had our system for 3 years and it has run fine so far until recently. The control unit ( Rychem NRG temp) for the system does not seem to trigger the mats to heat up in programme mode. If I use the manual ‘boost’ control the floor heats up nice and evenly. But in programe mode when a timed event is triggered the controler is showing the heating mat is on, with the target temperature is set for 23 oC, but the floor sensor is displaying 18 oC ( or the ambient temperature).
Any ideas?
Rgards
Mark

Hi Mark
It’s unusual to be working in manual mode but not in auto mode. I think it sounds likely that the relay in your controller has an intermittent fault so would suggest replacing the thermostat. Check how long the warranty period is on your thermostat although it’s probably out of date after 3 years.
All the best
Susan

My warm up underfloor heating system was not working and giving unusual readings I rang up the warmup team and they guided me through what to do. It is now working off of the air temp rather than the floor temp. Hope this helps. Gwyn

Hi Gwyn
Yes, this can be done but you do need an air/floor thermostat for this to work. Not all thermostats installed are this variety and may have a floor setting only. But I’m glad to hear you were able to get yours working again. The manufacturer helplines are usually very good if you are having problems.
Kind regards
Susan

Hi, working at a clients house and the tilers cut almost 12meters of a lose wire UFH cable out and then tiled the floor despite the tags on the cable saying not to shorten the cable. I measured the cut out piece of cable and it had 23 ohms of resistance. Is it possible to get an in line resistor that can make up for the missing cable as I’m sure that running the system as it is will damage the cable.

Hi Daniel
12 metres is an awful lot of cable to lose. That is a good question and I’m not sure if this is possible. I’d recommend contacting the manufacturer/heating supplier and speak to their technical department. They are usually very helpful. As mentioned in a previous post, we really don’t recommend shortening the cable, especially by this much. It’s far easier, cheaper and less problematic to get the right size in the first place, as you know 🙂
Kind regards
Susan

I have been reading all the responses and I’m interested to hear if you can help with my UFH issue. I bought a new build home near Edinburgh, and opted to have UFH installed in the en suite shower room. Within days of moving in we had reported that tiles on the floor were making a “clunking” noise as if they were slightly loose. The site manager appeased us with ” that’s just the floor settling” so we let this pass and basically lived with the “feature” for another 2 1/2 years.
In Feb 2016 the mat stopped functioning and I got an electrician to do a check on the thermostat and mat, the outcome of this diagnosis was that the thermostat was fine and that the loose fitting of the floor had caused the premature mat failure.
Needless to say the house builder is saying that as the mat is outwith their 2 year warranty period we have no claim against them! To repair/replace the mat is going to involve destroying the tiles, which were expensive. My question is would you expect a mat to fail after such a short time ? Also how feasible would a repair be to avoid lifting all the tiles?

Hi Stuart
No, the mats shouldn’t fail and generally most mats have between 10 years and a lifetime guarantee. If it is just one tile clicking, then it maybe possible to just lift a couple of tiles to find where the failure could be. But if the floor is clicking all over, it sounds as though the whole floor has failed. In which case, you may find the failure in one place, repair it but it could happen again in the future. Also note that if the grout has failed, the waterproofing protection it gives has been compromised.
Hopefully, it’s just the one tile and you can get this fixed.
All the best
Susan

Fully qualified Electrical here, looking at installing some electric UFH in my own bathroom at home
Now over the years i have been called out to many UFH faults sometimes faulty thermostat, sometimes the probe, or the mat/heating element itself
I Always install the probe in a tube or conduit, to try and give me half a chance of replacing it, but this time, on my own system i am going to install 2 probes,
My question is, i am also looking at installing 2 overlapping elements, or 2 side by side BUT ONLY CONNECTION ONE, as a backup (my floor is only 3m/sq)
If i do this, will one element damage the other?

Hi Peter
I can see why you would consider installing a backup incase of failure, but I would not install two systems either side by side or overlapping even if only one is to be connected. Personally I think it’s just asking for trouble and would probably be cheaper to repair the cable than installing twice the amount required. Generally failures of the mat or heating element are rare and if they do happen are usually caused by accidentally damaging the cable either during installation or upon later room modifications.

Whereas failures of the sensor or thermostat are more common, but these can be easily remedied (especially when you have a spare probe). I think this will be sufficient and wouldn’t bother with a 2nd element.
Kind regards
Susan

My warmup underfloor heating in the bathroom has started to over- heat. The thermostat shows 32 degrees and it is too warm underfoot. We do not seem to be able to turn it down on manual or automatic. Our only option seems to be off or too hot. Is this likely to be a disruptive complex repair?
The system is about 10 years old and gas had one previous repair involving the raising of a floor tile when the wire mesh ceased to work due to damage.

No, this isn’t a complex repair. You simply need to replace the thermostat. It sounds like it is stuck on due to failure of the relay.
If the floor is too hot to the touch, this is not good as it can overheat and cause damage.
Please turn off the underfloor heating and keep it off until you are able to replace thermostat.

I have recently had underfloor heating fitted in my conservatory by Speedheat.My floor covering is karndean and the installer said I couldn’t have insulation boards as it would damage the karndean so I went with his advice .The floor limiter is set at 27 degrees but the highest temp its reached is 20.5 on the thermostat and the floor isn’t exactly warm .I feel I should have used the insulation boards .

I can’t comment about Speedheat having no experience of them. However, the insulation is installed between the base floor and the heating element and not between the element and the floor covering. Therefore there shouldn’t really have been a problem doing this.
If the underfloor heating is not feeling warm though, it could be a problem with the heating system. Even with a poorly insulated floor you should still be getting some heat through. My advice would be to firstly check that it is working properly by going back to the installer and take it from there.

Hi, you have so many useful comments I’m hoping you can give some suggestions to us. We live in USA and had a Warmly Yours system installed in our bathroom in Fall 2012. This February it stopped working. The Warmly Yours support told us to have our electrician check the sensor. It turned out the sensor went bad. (Probably due to a leak we had in the shower that saturated the tiles & grout from underneath. We believe the leak was fixed in the Fall of 2014.) We are able to still use our system using the ambient air sensor but it seems to over heat the room when it is cool but not cold outside. Our electrician said they could probably install a new sensor in a grout line. So my question is there a type of sensor that is more reliable to be installed in a grout line? If we are having this work done should we install 2 sensors? Thank you for any help you can give us.

There isn’t really any type of sensor that is more reliable, at the end of the day it is just a thermocouple. From what you have said, it probably wasn’t the sensor that caused the underfloor heating to fail but the leak. If you can get two sensors into the grout line then I would this so that you can future proof any further fail by the sensor. Remember to wire only one sensor into the stat, the spare can usually be coiled up into the back of the stat.

Hi, After reviewing your really helpful responses to people’s issues I thought I might see if you can help me with mine. I’m pretty certain we have a ProWarm system and it was installed 2 years ago. it has worked absolutely fine up until 2 days ago when it just isn’t heating to the temperature it was across the whole floor, it isn’t a section that isn’t working. Looking at the thermostat it is doing something but all of a sudden it isn’t reaching the same temperature it was a few days ago, nothing else has changed and I’ve rechecked the thermostat settings. Do you have any suggestions?

Given the fact that your underfloor heating has been working for 2 years without problem and then stopped working completely, I’d suggest it is either a fault with the floor sensor or the thermostat, especially as you don’t appear to have isolated cold spots or had any other warning signs such as fuses blowing etc.

Even though a thermostat can appear to be operational it might not necessarily be functioning correctly. When we fit underfloor heating, the mats have a lifetime guarantee and the thermostats have 12 months. I bet you can guess which is more likely to fail first.

Generally if all looks normal it is probably the thermostat. Whereas if the thermostat is reading weird temperatures either very high or very low then it is probably the sensor.

I’d recommend you go back to your installer. Clarify if they have fitted a spare sensor which can be utilised to rule out that possibility. Plus confirm with them the warranty period for your thermostat. Replace as necessary.

We installed underfloor heating in a new kitchen extension. There are 2 mats. I wasn’t present when it was tested but my partner tells me both halves definately worked after the laminate was laid.
The 1st time we went to use it it doesn’t work in one half. I’m assuming there must be a fault at the joining of the mats?
As the join is near the french doors but in the middle of the room with the controlling unit under the kitchen units behind the kick boards is it possible to:
1. Locate the fault?
2. Will it be fixable?
3. Will the cost be prohibitive?

Hi John
As you have laminate fitted, do you have a cable mat installed rather than a carbon film or similar system recommended for laminate? I only ask this as cable mats are not really advised for laminate, this is because they need to be levelled over which creates alot of moisture that is unsuitable for laminate flooring. You have to leave the system to dry out for about a month before laying the floor covering and the underfloor heating tends to end up as a line heat. Laminate flooring is an insulator and the heat doesn’t spread evenly across when using cable mats, which is why a carbon film or similar product is recommended.

Anyhow, if you do have a cable system and there are only 2 mats, they are not normally joined under the floor but simply connected together in the control box (thermostat). Without knowing the precise configuration of the heating elements you have installed, I will presume from your description that you have 2 cable mats and that 1 is faulty.

I would first double check that they are both connected into the thermostat and if they are not, this can easily be remedied.

If both mats are connected then I’m afraid there is probably a fault in the mat. If you know where the fault is you can use our repair kit, but more likely than not you will have to call out a specialist UFH electrician to find the fault and repair. It will cost somewhere in the region of £400.

Fingers crossed that it just a problem with the connection into the thermostat.
Kind regards
Susan

Given that it is possible to repair a damaged wire; is it possible to shorten a wire in the same way. As far as I can tell, the internal cores are just connected together at the end and sealed.

I have installed a few of these systems and it is difficult to get the measurements spot on; often ending slightly short or slightly over and having to “lose” some excess. Being able to re-terminate at the exact end point would be very helpful on installation

Hi Paul
Agreed that you occasionally have to lose excess, but the solution is either to use a different size mat or to reroute some of the wiring into the gaps. Rerouting into the gaps must be done carefully however, because if there is too much cable and they are laid too close together it can cause potential shorts in the future. Sometimes, the mat is just too big. We would certainly not recommend shortening the wires.
Alternatively, if the mat is too short, you can pull it off the webbing and space out the cables out a bit more.
Ideally, you want to be measuring the mat size accurately which is generally a minimum 85% of the total floor area less any obstructions such as a drain etc.
I hope you find this information useful.
Kind regards
Susan

Hi, we’ve seen your really helpful responses and wonder if you can help us? We are extending our kitchen and don’t want to take up the tiles on the exisiting kitchen floor (laid directly on concrete, no underfloor heating). In the new part of the kitchen we will be installing electric underfloor heating and ideally then tiles to match the existing floor. Our concern is that where the new (heated) tiles meet the exisiting (cold) ones we might get cracking due to the temperature differential. Have you experienced any jobs like this and if so do they have that problem? Many thanks

Hi David
I think that you will be fine when you fit the new underfloor heating and tiles and you shouldn’t really experience any problems when butting up the heated and non-heated tiles. The reason for this is that the mat itself should always be fitted with a gap of around 150mm (6 inches) from the external wall or in this instance to the end of the new tiles. Therefore the final tile or adjoining tile should in reality be only half cold and half warm.
To make doubly sure, you can use an expansion joint between the two sets of tiles but as you are using matching tiles you may not be happy with the look this will create.
I hope this helps
Susan

Hi,
Our kitchen electric pad underfloor heating has worked for 5 years. Since Nov we are having a kitchen extension and the travertine floor was protected with hardboard & not damaged as far as we can see – the tiles look perfect. The kitchen was partitioned with boards across the middle so one half was in the warmth of the house & the other was in a very cold space, for a couple of weeks water was making its way in a little but the chipboards kept the floor from being fully wet, however the temperature in that part dropped & felt damp. We noticed the floor didn’t warm up one day, then it did work again after we reset the timing, then it stopped again & won’t come on at all. Can you suggest why?? Was it the temp difference, wet through the grout or vibration from the build that could severed the cable?

Hi Rachel
Apologies for the delay in responding.
Based on the information you have given, I very much doubt it is any of the things you are suggesting. Occasionally, after periods of inactivity the thermostat relays fail so this could be the problem, especially as it did work briefly when reset. Incidentally, floor sensors can also fail randomly.
I would recommend in the first instance speaking to the thermostat manufacturer as replacing this may resolve the issue your are experiencing.

Hi, I have had three underfloor heating mats installed in a kitchen/dining/utility extension. 2 x 7m2 mats operate through one thermostat/controller and the other 2m2 into a separate thermostat/controller. All of the mats have tails sealed with a heat shrunk sleeve joining the heated mat to the cable and at least one of the mats has a tail which is more or less completely exposed and in free air behind the skirting boards. One of the 7m2 mats has stopped heating and there is no resistance at the thermostat end of the tail. My suspicion from all the other comments is that the heat shrunk joint should have been buried under adhesive or self levelling compound and that it is this joint which has overheated. Should I remove the heat shrink and test the resistance at this joint? It there is a good resistance, is it then an easy re-join followed by installation of heat shrink and burial of the cable?

The cable should have been laid in adhesive as you suggest, I would imagine that the end joint of the cable has burnt out and needs an End Repair Kit to fix the fault. Once repaired, this should then be laid in adhesive.

Although the End Repair Kit isn’t displayed on our website to purchase, if you simply order the Middle Kit and add to the special instructions that you want an End Repair Kit instead, we can send one of those – they are the same price.

We had a new heated flooring system installed 3 days ago. We were told it was a 240V system so when the electrition came out we had the panel and wires set up for 240. We turned it on and nothing happened. Later in the night the GFCI blew on the thermostat so we reset it but still no heat. Electrician came out and realized it was acrually a 120V system not a 240. He put the omming tool on and it sent him back nothing. He said the system is fried 🙁 is there anything we can do? Or do we now have a $600.00 heated floor system we can’t use under our brand new tile?

Hi Nathan
I’m afraid I can’t really help you with 120v systems as all the ones we use are 240v. Every single one.
But if it is the case that you have had a 120v system installed but with wiring for a 240v system, then I can only imagine the system is fried, like the electrician has advised you. It’s a pity it wasn’t the other way round then you should have been okay.
Your only come back I’d say would be to go back to whoever supplied and fitted it for you. I presume it was them that advised you incorrectly that it was a 240v system. If so, they should take the responsibility for this costly error.
Good luck
Susan

Hi there
Out electrical mat in the kitchen (concrete floor) was installed 4 months ago and worked fine until a couple of days ago when in stopped producing any heat.
The room stat (set at 22 deg) shows floor tempersture as 45-60 deg depending on weather conditions.
I suspect the floor sensor has been compromised as the grouping is cracking and lifting. I’d rather not replace this as the cable runs in a conduit behind plaster, behind skirting before going under the tiles
Q. Can I use a room thermostat to activate the heating mat (via the existing programmable controller) or is the only option to lift tiles and replace the sensor?
Any suggestions/solutions appreciated
Many thanks

It definitely sounds as if your sensor is compromised. When we fit underfloor heating, it is not recommended to use a stat which uses an air sensor to control the system. At the end of the day, they are floor heating systems rather than room heating systems.

We always install a spare sensor which is curled up in the rear of the stat. Can you check to see if the company who installed your system did this too? A long shot I know, but you never know.

However, I would be more concerned about why the grout is lifting after only 4 months. This shouldn’t happen and might mean that your floor has failed. If you find it happening in more places over time, it may be necessary to lift the whole floor and replace. Hopefully, this is not the case, call in a professional tiler to check it over.

If you replace the sensor, you maybe able to drag the new one up the conduit by using the old sensor but it depends on how much wiggle room there is in the conduit. But I’d suggest getting the floor checked first as it could be a lot of effort only to find out later that all the floor has to come up.

Hi there we have just had a warmup mat installed in ensuite. Worked for a few weeks but then started becoming irregular in terms of the program times we had set and then the floor sensor error came up but it still seemed to be heating up but today it is not heating up and there are no temps showing on the control box still with floor sensor error. Will we have to lift the tiles?

Hi Rebecca
It seems strange that it only worked for a couple of weeks and then has started playing up. There are a couple of things you can do.

Speak to Warm Up. It’s best if you’re at home with access to the stat etc so that when you are talking to customer services they can guide you on any changes to make. It maybe that simply resetting the thermostat to default settings and then reprogramming it from scratch will fix the problem.

Or yes, the stat might be right in that you have a faulty sensor. Many, many years ago when we first started installing underfloor heating we were incorrectly taping down the sensor and unfortunately this interfered with the operation of the sensor (hopefully yours wasn’t installed this way). If it is determined that the sensor is faulty, hopefully you will be able to dig out a grout line between the tiles and replace the sensor without having to dig up a tile. Digging up a tile is the worst case scenario, but you can do it, you just have to be very gentle and go slow (and you need a spare tile too!).
Good luck
Sue

Here is a tricky one. I installed 2 electrical heating mats (OJ electronics model UCCG) in my bathroom connected to one single sensor and control unit. It is under tiles, that seat on a concrete floor (which means the floor is very solid and does not move with time). The whole system worked fine for 3 years. And just yesterday, one mat stopped working, and bad luck, it is the one where the sensor is embedded. I did test it, and the tester signals a short cut in the mat (no current goes through it).
Question 1: How is it possible that a mat stops working after 3 years, without any physical aggression?

Question 2: in your blog, you mention that electricians use thermal camera to locate the damage area. If no current goes through the wire, how can they detect where is the cut?

Hi Frederic
It is possible for a mat to stop working after 3 years if there is a slight kink in the cable or a leak to earth. This can get worse over time as the corrosive elements in tile adhesive attack the weakness eventually leading to a short and failure. In fact I have experienced this myself and was lucky enough for the failure to be covered by the manufacturers warranty.

I am not fully informed with how the imaging camera works but they were able to use this with my fault which kept tripping the main fuse box. There are other techniques that they use too such as determining the distance of the fault from the thermostat (I can’t explain this one either I’m afraid). But I do know that electricians experienced with underfloor heating systems can find these faults and fix them when the location of the fault is unknown.

Obviously the cost can be quite prohibitive, however the costs may be covered by your manufacturers warranty, especially after only 3 years. Ideally, go back to the company who installed your underfloor heating or failing that go direct to the manufacturer.

I recently had an extension built and agreed to install electric mat underfloor heating to the extension and back room. The extension heating works fine, tiles are lovely to walk on.

The heating in the back room however, only worked very briefly. I had the radiator removed. The original laminate boards were replaced with porcelain tiles laid over floor boards with the heating mat in between. The thermostat is currently at max but the tiles are freezing. The builder came back and assured me that there was some heat, that because it was over a ground floor with a space the heat was dissipating below. I’m no expert but i’m not convinced. Should i feel an appreciable increase in the floor temperature? What should I do next?

Hi Mike
Good to talk to you earlier today.
Just to confirm our discussion, when fitting tiles over floorboards with underfloor heating we would recommend using a tile backer board. You need to take out the flexibility of the floorboards and create some rigidity and using tile backer boards is more beneficial than simple ply as it also has insulation properties. You said that you would check with your builder. As I said, if it is only normal ply, than yes this would diminish the effectiveness somewhat, but you should still be able to notice some warmth however limited. You only need to feel a tile not heated in comparison with one with the underfloor heating when on and you should pick up a difference.

Given the fact that it might not have worked from the beginning then perhaps the wiring, sensor or stat would be the other culprits to check into. It might even be the programming of the stat. The ones we install use a fall back temperature that you need to set, so that the mat isn’t always trying to heat up from its lowest setting. I have mine set at 16 degrees as the minimum, then when it comes on it is already 16 degrees and will increase warming from this temperature.

I am looking for under floor mat heating engineer. I believe mat wire was broken somewhere and want to identify, break the tile etc.. to fix the problem.
Please can you share the contact details of engineer? how much it will cost to fix?

Hi Shri
There are a number of specialist underfloor heating engineers listed on the internet, and most offer a nationwide service.
In the first instance though, I would always recommend contacting your installer and failing that the manufacturer of the mat as most manufacturers these days offer a lifetime guarantee (based on correct installation). It is the biggest worry for customers when choosing to fit underfloor heating so the guarantee is there to give peace of mind.
If you have to foot the bill, then you could be looking at £300+ to fix, so it would be better if you could claim under a manufacturers warranty.
Kind regards
Susan

Our bathroom had underfloor heating -loose cable, not the mat-installed one – around 10 years ago, the thermostat is a Warmup. It has worked very well all these years in constant use but has suddenly stopped heating this past week or so, although the thermostat still shows a readout and appears to be working -the temp now will not go over 17, which I think is the house ambient, even when raised to 28 on the Warmup thermostat. Is there any hope of finding the fault without ripping the bathroom up? We do not have any paperwork or installer details. Any advice appreciated.

Hi Laurie
Do you have any receipt or paperwork to confirm that you purchased a Warmup system. Warmup have their own engineer who can visit to help identify faults and they also provide a support helpline you can call. It sounds to me that something has probably gone wrong with your clock and the relay has possibly failed, so you will need a replacement thermostat. You can replace like with like if the one you have is still available, or we have one available too at http://goo.gl/38dNPF.
Hope this helps
Sue

No proof that it is a Warmup system other than that the wall thermostat unit is a Warmup one and it seems to be the (verbal) recollection that the kit came from Topps Tiles and was a Warmup kit. Warmup are not particularly helpful – they want you to sign up with a valid credit card they can dip into, for unlimited costs relating to their engineer visits – even if they don’t bother to turn up on time! Will take a look at thermostat and see if it can be replaced like for like, seems a sensible start .

Hi Laurie
Sorry, I wasn’t aware that you had to provide payment information beforehand with Warmup incase of incurring any possible costs. In their defence, I imagine they have more than their fair share of problems caused by incorrect installation and as fixing costs are quite high, customers maybe less inclined to pay onsite. Regardless, I’d definitely try replacing the stat first off as it’s the lesser of two evils. And if it isn’t faulty you’ll have a spare to fall back on (they usually only come with a 12 month guarantee anyhow). Let’s hope that this works.
Kind regards
Susan

I am assuming that the underfloor heating has worked prior to this but there has been a change to its normal workings. If you do not have any heating and the thermostat is behaving oddly then it is more than likely that the stat has failed or the sensor to the stat has failed. Can you reset the thermostat to the default settings? Is there a spare sensor installed?

I would suggest contacting your original installer or the customer services department of the thermostat manufacturer Heatmat for their assistance. Generally the mats themselves have a lifetime guarantee and the sensors and thermostats 12 months.

I bought a new build flat 7 years ago with NIBE underfloor heating. It worked fine until now. All rooms are warming fine. The issue is only in the living room where half of the floor is heating up and half is not. Its a laminated floor. The guarantee ended two years ago. Is there anything I can do to find out the fault. I think its the actuator thats not working, but how do I find out which actuator it is. Secondly, this winter I have noticed that the thermostat does not activate the heating until its increased to 20 degrees. Any advise please and do you have any estimate of how much will it cost if I call in an engineer.

Hi Amir
Thank you for your enquiry.
I’m afraid that we are not experienced in the installation of heat pump underfloor heating systems such as NIBE, our knowledge is of electrical systems only.

So far this winter has been quite mild so it might be that you are needing a higher temperature on the thermostat to activate the heating.

As the property was a new build, I would suggest getting in touch with the builder and asking for the contact details of the NIBE installer as it is likely to have been a specialist subcontractor. They would then be able to quote you for a site visit and help in rectifying the problems you are experiencing.

We are renting a house with underfloor heating but have been having problems with it from the start. The heating in the bedroom and bathroom seem to come on even when the thermostat is off. It gets so hot at night that we have to keep the main thermostat dial down low to keep the heating off, but this means that the rest of the house is also cold despite setting the individual thermostats in the rest of the house to 30 degrees! We are also using a lot of oil, about £60 every 2 weeks. The landlord is not being very helpful, he had a plumber out to change the thermostat and service the boiler but that didn’t work, now he’s dragging his heels and we’re not sure what to do next… Any advice would be greatly appreciated!

Hi Natalie
If you’re using a lot of oil, then I guess you have a water based underfloor heating system. Unfortunately, we only install electric systems so do not have the experience in water systems to be able to advise you correctly.
Something is amiss and I’m afraid you’ll have to persevere with your landlord to get it fixed by a specialist water based underfloor heating installer.
Kind regards
Sue

Our 2 bedroom flat has the original electric underfloor heating system. It works throughout, but is no longer controlled by the thermostats. Unfortunately it has to be manually switched on and off at the meter – otherwise the flat overheats, resulting in very large bills. The thermostats are GEC and the flats were purpose built about 1960. There are 12 flats in a well built 3 storey block. Most flats have had problems and have switched to gas central heating. Can you advise a way forward please?
Best. Bernard

As you say your system was installed in the 1960’s, I can’t really say whether it will work in a similar fashion to one from today. And few electricians from that time would have experience of their workings too so it would be hard to track one down who could help.

If it was a modern system, I would say that your thermostat and underfloor heating are not talking to one another. Either the sensor telling the stat the temperature is giving a false reading or the stat is getting the reading but is failing to regulate it coming on and off to keep to a steady temperature. Unfortunately, I don’t know how your mat is connected to the stat and if the GEC stat you have works in the same way as a new one.

You could try getting hold of an electrician to disconnect the stat and see if he can identify the connections but I think that finding the right person may take some time. There are forums online for tilers and I’m sure ones exist for electricians. Perhaps post and enquiry and you never know who might be looking.

I’m sorry I can’t give you anymore help, it would be great if you could use what is already there.
Let me know how you get on
Sue

Hi Maria
We had our underfloor electric cable wire heating installed 4 years ago, all this time, we had no problem whatsoever, over the last weekend, we noticed that the Warmup 31e thermostat had gone blank and no heating.
We do have the power switch which shows that power is coming on and I have changed the 13 AMP fuse, but still thermostat is blank and no heating .
Can you please tell us as to what could have gone wrong
Kind regards
Imtiaz

Hi Imtiaz
You need to make sure that power is going to your thermostat. Have you checked the supply with a multi-meter? I would recommend contacting an electrician to check this for you. If it appears the power is going to the thermostat okay but it is still blank, it is possible your stat might have failed. What is the warranty given by the manufacturer? If still under guarantee you maybe able to arrange for a replacement. Alternatively, if you contact the manufacturer directly, they may have someone available who can check and repair the fault, although a charge maybe made for this service.
I hope you find this useful.
Sue

Hi Maria
Do you have a water based or an electric underfloor heating system? I would suggest going back to the vendor to find out if they can remember the make, how long it hasn’t been working or how to get it to work if they had it working? Will the manufacturers warranty still be valid and does it pass to you following the sale? If there is still a problem and it is an electrical mat, to identify the potential failure you need to go through each of the steps in the article: sensor, thermostat, electrical, before determining if there is a break in the mat which is the most expensive to fix and find. Unfortunately, each of these measures do have cost implications but can be cheaper than installing a brand new system.

Hi Thomas
I’m afraid we only install electric underfloor heating so cannot help you with a water based system. Your best option is to contact the manufacturer or a plumber with water based underfloor heating experience.
Kind regards
Susan

I have a problem with my electrical heating mat, the thermostat works as I have change this as I thought that was the problem. The problem is that the heat is not coming from the heating mat however the light on the thermostat is working. Either is the electricity is tripping.

Hi Jayshiva
You didn’t state whether your underfloor heating has ever worked or just stopped working. On the basis that your underfloor heating has been working previously and you have changed the stat then the problem either lies with the sensor, the connection between the mat and the power supply or the power supply and the stat, or in the mat itself. I would recommend calling in an electrician to check out the accessible part of the connections and associated wiring. A fault within the mat itself will often cause the fuse to trip.
Hope this helps
Susan

Hi, we had electric (mesh mat) underfloor heating installed may 14 by a “pro self implored” chap but our electrician wired everything up. On a few occasions (more so recently) I can smell a warm plastic type smell, hard to describe coz not exactly burning! More like the first time you put your heating on for the first time after 6 months off. I also swear I have seen the thermo on the wall ‘flash’ but everything seems to be working just fine. My husband has turned down the thermo temp a little, now max 23 degrees. Can you help with any advice!
Thanks, Chris

Hi Chris
Thanks for your message. You shouldn’t be able to smell anything. I don’t know what type of floor covering you have on top of your underfloor heating but whatever it is would probably exclude any smells becoming noticeable above. I had a cable mat that was burning through in one area underneath tiles and couldn’t smell a thing. It sounds more likely that the fault lies between the mat and the thermostat or power source (a fused spur). My recommendation would be to get an electrician to check the wiring in these areas. Maybe this might explain the possible flashing thermostat.
Hope this helps
Sue
.

The good thing is that your underfloor heating is working. Do you know if the system installed was a cable mat with webbing or just a loose cable? Underfloor heating does not provide a solid heat completely across the floor, but simply spreads it out. The closer the cables are to each other or the further apart they are will affect the warmth from the floor. But don’t be tempted to have them too close as it can cause them to short.

Unless you are fitting in an unusual shaped room such as a bathroom where a loose cable system is best, we always recommend using an underfloor heating mat with webbing as this provides the ideal spacing between cables to spread the warmth evenly. It maybe possible in your case that the mat fitted was a little too small for the area and the cables are slightly further apart so that cooler spots are more noticeable. Or perhaps there are areas where the cable was missed. Do you have one or more mats fitted? It is not inconceivable that one mat is working and another is not. If you only have one mat, it is unlikely that the mat is faulty as it would either be warm or cold rather than patchy.

Other things to consider are what flooring have you fitted on top of the underfloor heating? If tiles, was a self levelling compound used to encapsulate the wires prior to fitting the tiles? Have you also fitted insulation under the mat system?

All of these factors can affect how you try to remedy your patchy underfloor heating. I suggest you contact the person who fitted your system to find out this information and help eliminate possible causes. I hope this helps.

We bought our flat 4 years ago and the underfloor heating already present in our bathroom has never worked. We have zero paperwork for it and the thermostat control has never binged into life to give any kind of reading so not really sure how to categorise the fault based on this very helpful article. Does anyone have any advice..? I’m guessing perhaps replace the thermostat to see if that does the trick and go from there..?

Hi Hannah
Although there are many different manufacturers of electric underfloor heating mats, they all tend to work in a similar fashion, so it is possible to fix them without necessarily knowing the make. However, if the mat was found to be faulty you would need a receipt to be able to claim against the product guarantee.

Rather than assuming your thermostat is faulty, even though it might be. In the first instance, my advice would be to find a local electrician with experience of wiring up underfloor heating mats. You can’t tell whether your mat or thermostat have been wired in or power supplied correctly and it could be as simple as this.

Hi.
I have problem with under floor heating in bathroom.
tripping fuse in electric board, I checked Thermostat is faulty and I change, is still tripping fuse if hitting is coming on also Termostat show my problem with sensor but if hitting again is coming on fuse is tripping. i checked coniunity with a multimeter show mi 650mA. Please tell me what i need to do?
Thanks Tom.

I’m sorry to hear about your problem with the underfloor heating in your bathroom.

Unfortunately, it sounds as though you have a short somewhere on your underfloor heating mat. It could be on a joint or simply where cables have been fitted too close together. The bad news is that this is the most expensive problem to fix because you cannot tell exactly where the short is on the mat. For this you need to get an specialist underfloor heating electrician in to identify the exact location of the fault. They use professional fault finding equipment and imaging devices to pinpoint the problem. You should be able to find one locally searching the internet or some repairers do offer a UK wide service. Remember, you maybe able to claim for the repair if it is found to be a manufacturing fault (dependent upon the product guarantee).

I was thinking of having underfloor heating installed when my friend had hers done, but after a few weeks only half her kitchen floor was working! She never bothered with the expense of getting it repaired. I have heard that the wet systems are more reliable but also more expensive, what is your experience? Are they a better option or do they come with their own set of faults?

In my experience, this is most unusual. It is the sensor or thermostat that tend to fail first rather than the mat. It sounds as if your friend must have had at least two mats fitted in her kitchen. Did the second mat work in the beginning or could it have been wired in incorrectly? Was it fitted correctly? Overlapping mats or laying them too close together can cause the wires to short over time. Or it could be a manufacturers fault, in which case the repair could be carried out at the expense of the manufacturer under the product guarantee. For me, I would prefer to get the underfloor heating repaired rather than have half the room cold or have to turn it off completely.

We fit underfloor heating in homes every week and mat failures are quite rare. We have been fitting Varme mats since 2005 and they offer lifetime guarantees which I’m sure they wouldn’t do if failure rates were high. Do remember, there are many different brands of mats from which to choose and obviously quality and reliability can vary.

I have limited experience of wet systems. From what I have gathered, they are not necessarily any cheaper to run and the existing boiler maybe insufficient to cope with the extra requirements necessary when adding it to a current heating system. It is also necessary to use a de-coupling mat when tiling over water based systems to prevent any cracks from the screed. If the mat is not used, then these movements can cause cracking in the tiles. Obviously adding the mat is an extra expense. Apart from this, I have no further knowledge regarding their operation as we specialise in the electric mat system.

i had underfloor heating installed …all parties admit that was a fault from the beginning
ie one of the mats is not working
have been told that i have to wait more than 6 weeks (from the date it was decided that there was a fault to when the engineer can come out.
can this be acceptable practice …if a washing machine or tv broke you would not expect to be told to wait for 6 weeks…. the engineer covers the UK so is it because i live in rural East Yorkshire?

It can depend on the manufacturer of the mat supplied. Some manufacturers have in-house engineers to manage faults so they may have shorter lead times. However, in my experience a wait of 6 weeks before an engineer can call out is not unusual especially during the winter months when you tend to experience a peak in queries.

Fixing electric underfloor heating is a specialised service with few electricians offering this facility, consequently demand can mean a wait of some weeks before they can get to you rather than it being dictated by where you live.

Although you have the inconvenience of waiting, at least you won’t have to foot the bill which can be several hundred pounds.